Filter when

[Phil_Cheeseman]

We are moving from SAP Business Objects to Looker  , one of the features of that tool is something called contexts .  So if i choose Sales £  it shows me all the sites with sales and ignores something like a warehouse , but if i choose stock  as well it will show sites with stock and sales .   

I thought it would be something like a condition  WHEN SALES_£ then X locations .  however i cant see how this is possible with out the user actually adding the filter .